Research how to keep trolling to a minimum. If it’s an open multiplayer world, how do we keep people from trashing other people’s stuff? Access permissions? Do we instead have access permissions per “world”? You can have a world with your friends or whoever you invite?
It would be interesting if a person could choose who’s stuff was near theirs - that they could build their own map of worlds/servers.
Multiplayer “Play Scene”? Perhaps a player can just put themselves at the starting “position” of the scene? Still, they may want timed things, like a cave collapse. Pause and rewind (https://www.youtube.com/watch?feature=player_detailpage&v=PUv66718DII#t=762) for single player only? Is there a way to show predicted movement in multiplayer?